Fat continuous food products are well known in the art and include for example shortenings comprising a fat phase and water in oil spreads like margarine comprising a fat phase and an aqueous phase.
The fat phase of margarine and similar edible fat continuous spreads is often a mixture of liquid oil (i.e. fat that is liquid at ambient temperature) and fat which is solid at ambient temperatures. The solid fat, also called structuring fat or hardstock fat, serves to structure the fat phase (being the case in for example a shortening as well as in a water in oil emulsion) and helps to stabilize the aqueous phase, if present, by forming a fat crystal network. For a margarine or spread, ideally the structuring fat has such properties that it melts or dissolves at mouth temperature. Otherwise the product may have a heavy and/or waxy mouthfeel.
Important aspects of a fat continuous spread like for example margarine and low fat spread, the low fat spread usually comprising from 10 to 40 wt % fat on total composition, are for example hardness, spreadibility and ability to withstand temperature cycling. Temperature cycling means that the product is subjected to low and high temperatures (e.g. when the consumer takes the product out of the refrigerator and leaves it for some time at the table to use it). This may have a negative influence on the structure of the spread (like for example destabilization of the emulsion or oil-exudation).
Generally edible fat continuous food products like for example margarines and similar edible fat continuous spreads are prepared according to known processes that encompass the following steps:    1. Mixing of the liquid oil, the structuring fat and if present the aqueous phase at a temperature at which the structuring fat is definitely liquid;    2. cooling of the mixture under high shear to induce crystallization of the structuring fat to create an emulsion;    3. formation of a fat crystal network to stabilize the resulting emulsion and give the product some degree of firmness;    4. modification of the crystal network to produce the desired firmness, confer plasticity and reduce the water droplet size.
These steps are usually conducted in a process that involves apparatus that allow heating, cooling and mechanical working of the ingredients, such as the churn process or the votator process. The churn process and the votator process are described in the Ullmans Encyclopedia, Fifth Edition, Volume A 16, pages 156-158.
A disadvantage of these processes is that the complete composition (including the liquid oil, structuring fat and if present the aqueous phase) is subjected to a heating step and a cooling step. This requires a lot of energy. For a spread comprising for example 6 wt % structuring fat the whole composition (100 wt %) has to be heated and cooled.
Another disadvantage of the known processes is that the choice of fats that can practically be used as structuring agent is rather limited. If the melting point of the structuring agent is too high the melting properties in the mouth are unsatisfactory. If on the other hand, the melting point is too low, the emulsion stability will be negatively affected. Moreover the amount of saturated fatty acids (SAFA) in the structuring agent is usually relatively high. Also trans fatty acid may be present. Some experts have called for reductions in these fatty acids to improve cardiovascular health.
Some consumers prefer spreads that have a low energy density (for example products that are low in total fat) and/or are low in SAFA but still have a good nutritional profile (by providing for example essential fatty acids like omega-3 and omega-6).
A further disadvantage of the known processes is that the product may deteriorate due to the changes in temperature caused by the heating and cooling step.
Alternative processes have been described wherein the structuring fat is added as fat powder (i.e. crystallized fat) thereby eliminating the need to heat the whole composition to above the melting temperature of the structuring fat.
EP 1285584 A2 discloses a method to prepare a margarine encompassing taking the solid fat component, together with a minimal amount of the oil phase, cryogenically re-crystallizing it and then combining it with an emulsion of the aqueous phase dispersed in the remainder of the oil phase or by adding the oil and aqueous phases sequentially. The disclosed shortenings and spreads contain relatively high levels of structuring fat (e.g. 25 wt % or more). Furthermore, the structuring fats are partly or fully hydrogenated.
Food Ingredients and Analysis International Vol. 23 No. 4 pages 29-30 (2001) describes powdered fats based on cryogenic technology that can be used for example in pourable margarines and different types of soft fat spreads. It is however mentioned that powdered fats may be used in combination with liquid oil, but for optimal performance these products need a specially designed fat composition which is crystallized from the melt. This will give the best structure of the crystal fraction, and allows a stabilizing network of crystals to be formed during cooling.
EP 1651338 A1 discloses a process for the preparation of an edible dispersion like for example margarine, wherein the dispersion is formed by mixing oil, solid structuring agent particles and an aqueous phase and/or solid phase. The solid structuring agent particles have a microporous structure of submicron size particles. The solid structuring agent particles can be prepared using a micronisation process.
We have found that using fat powder to make a fat continuous spread like for example a low fat spread may not always result in a spread of predictable and/or acceptable quality for the consumer on aspects like for example stability, structure or nutrition, and depends at least in part on the quality of the fat powder itself.
It is an object of the present invention to provide edible fat powders that can be used to make a fat continuous food product of predictable quality, more specifically to make a fat continuous spread, like for example a margarine or low fat spread, of predictable quality.
Another object of the invention is to provide edible fat powders that can be used to make a fat continuous food product with improved properties like spreadibility and/or heat stability and/or hardness, more specifically to make a fat continuous spread, like for example a margarine or low fat spread, with improved properties like spreadibility and/or heat stability and/or hardness.